Imfeoyement is sewim-michffles



geiten tetes stmt ffire.

IMPROVEMENT" 1N servire-MACHINES.

SPECIFICATION- TO ALL WHOM IT MAY CONCERN: l

Be it known that I, T. REED, `of East Bridgewater, in the county of Plymouth, andState-of,lldassaclnb` setts, have invented an Improvement in Sewing-Machines; and` I do hereby declare that tlie following, taken in 1 l connection with the drawings which accompany and for'm part of this s'peciiication, is a description of myw invention suihcent to enable those skilled in the art to practise it.

In all sewing-machines in which shuttles are used, more or less difficulty occurs in `adjusting 'the tension upon the shuttle-thread. So far as I know, in all such machines, the shuttle has to be removed or takenjfrom theV machine everytime the tension of itsthread is to be changed ;4 and las every `lrenioval `breaksI the thread, and thereby weakens the stitch, and as, generally, the tensionis brought tlolproper',` adjustment only i by repeated trials, it is an important desideratum to be ableto manipulate the tension `device without removing the shuttle, and still more important to be able to eiifect the adjustment whilelthe machine is running. Toeffect these results is the object of my invention, which,broadly stated, is to i. combine with the] tesion device fr 3 .sewnganachine shuttle and the Vcooperative stitch-forming mechanism, a melchanisniloperated from the ontside of the sewing-machine framework or table, to actuate thetension devicewhilethemachine is'irunningaand to thereby adjust or increase or diminish the tension upon the shuttle-tliread,` as circumstances mayrequirel I The' drawings represent so much of the mechanism of a Florence sewing-machine as will enable my invention, shown as applied thereto, to be clearly understoodi i I y t A, showing a plan of the shuttle-race and mechanism adjacent thereto. B, a section on the red line shown in A. C, a View of the open side `of the shuttle.

a denotes the shuttlelcontaining `case, the top plate of ,which (not representedfin the drawingsllforms the, i work-supporting surface. As the feedand stitch-forming mechanism are not at `allcl`1i.l.`\,te`d,sf'rfar asilrelates ,to yg ,feeding the work and forming the stitches, the needle, presser-foot, and feeding-,device are 3omitted` from the drawings, in order to show more prominently-the mechanism for carrying out myinvention.` b `denotes the shuttle-race; c the fshuttlc; d, `the bobbin thereof; je, the hinged tension-plate,stressiupon which,.to"create i pressure upon the bobbin-thread, is exerted by a C spring, f, me endofwhichis hooked `int-cm1 ,arm extending' from the tension-plate, while the other end has a nut or screw-thread formed in it, ,intoiwhich a screwf thread or shaft, gyworks. The tension-plate is hung inbearings in the shuttle, and thearm'ltowhichqthe spring vis applied extending ,down below `one of `the bearings,the pressure of thespringforcesi the plate `against 1the i threadandmakes the tension. turning the screw-shaft g, and thereby cramping the`spriiigjlIllQlior less, this pressure is increased or diminished, as may be desirable. As usually applied, this shaft has areeesed head on one end for application of a screw-driver, and to'regulate the tension, the `slrlnttle is removed,.and-the f screw turnedtovadjust the stress ofthe tension-spring. I apply to thescrew-shai't a-smallspurfwheel orpinaion, h, by turning which the screwis turned, and the spring cramped more or less, in accordance withthe direction in which the wheel is rotated. A groove, z', is formed at each endof the shuttle, in theplaiieofithe whee1,i"as i seen at C. ,Through the side wall le, of the shuttle-race, two holes, l, are made `in 1 the hrizontal.plane` of` `the l wheel h, and through these' holes the inner ends of 'trio slide-rods, m, work,`thei1j outer, ends extendingfbeyond f the outer side of thebox or casing a, as seen at A. The ,inner end of each of `these `slides `'misformed withl `spur-teeth n, and-each has `a springfo, applied to it, the tendency of which is to carriy` the slide intoitheposition i shown in section at A, (this fragmentary section bein g taken in the line of the` spur-wheelh.) The extent fof slide islimited by` a shoulder, p, which brings up against gthe face of `the shuttleraco. When in this position, the teetlr'on the slide project into the path of the teeth of the spur-wl1eel, so that the inward movement of the as the shuttle ilie's' in the direction denoted by the arrow thereon, the teeth on the slide will strikethe .wl`1eel,

and slightly rotate it, and thus cramp. up the spring 'and increase the tension., "The section atAshows lthe, spur-wheel as haying been `operated. upon by the slide, and as having gone beyond `ityand before"theirodisl returned'to its normal position, which return takes piace during `the continued movementof theishuttlein the same directin, or before the spur-wheel again comes opposite to the slide, in its return movement.` when the other slide is forced in by its spring, the spur-wheel is struck by the spur'on the eind of said slidpas the shuttle dies in the opposite direction, and the tension-spring shaft is 'thereby so` turned las., t lessen the` stress; -upon the spring, and diminish the tension on the thread, the slide being` carried back before the Sprit-wheel again comes opposite thereto. 4Each slide has a spring-latch, q, (see the section 1),) by which it its` hitched` in normal position, the latch locking against the` case of the facing a. By depressing the latch with the hand, either rod will be carried in at the proper time, by its spring, as will be readily understood. lThis proper time, and the throwing the spur of each rod out of' thepath of the spur-wheel, after each` engagement, is determined and regulated as follows: each slide, adjacent to the wall of the slinttle-racehas a projection or friction-roll, r, on its lower surface, and just below these rolls or' projections is a sliding-plate, s, having two projections, t,.this plate being hung on two pins, u, and having a reciprocating endwise movement imparted to it by the shuttle-driverv v. This plate bears two inclines, w, which act upon the rolls or projections Whenever either slide m has been pressed into the path of' the spur-Wheel. This action of the incline takes place immediately after the action ofthe spur of either slide m upon the'spur-Wheel on the tensioni-spring shaft, orV just at the end ofthe motion'of the shuttle, in either direction, the incline acting upon Vthe roll or projection, and driving back the slide, the latch at the outer end of which springs down and locks thefslide in normal position. In this normal position, the inclines pass between each roll or projection and the outer-wall of the shuttle-race, Without striking or aiecting the position of either slide. It will thus be seen that, no matter how fast the machine may be running, the tension upon the shuttle-thread may be regulated or varied, at pleasure, Without removing the shuttle or stopping themachine, and that .the Itension is increased or diminished according to the rod manipulated. By freeing the latch on either rod aftereachmotion of the shuttle, the tension-regulating screw may be turned to any extent required. It will be obvious that this mechanismv may be greatly varied -for'diil'erent styles of machines or shuttles,lor in the same machine, .many modifications having occurred to lmyself; but vvith this style of machine, I consider the mechanism shown to be'as reliable and effective as any. In a shuttle'like that shown at E, a modification will be necessary, which will drive the plate 2:, (between which and the .shuttle-face the thread passesgmore or less in one direction or the other, as the'ten'sion is to be increased or diminished. Y l y I` claim combining with the reciprocating shuttle andI shuttle-race of a -sciting-machine, a device or mechanism, operated by the movement of the` shuttle to regulate or change the tension of the shuttle-thread, substantially as Aset forth.

n T. K. REED. Witnesses:

F. GoULn, M. W. Faornmenm.

maar 

